JUSTIFICATION OF THE TEMPERATURE DEVIATION OF THE HEAT CARRIER AT THE OUTLET OF THE WELL OF THE GEOTHERMAL HEAT PUMP SYSTEM AS A FEATURE OF THE HYDROGEOTHERMAL REGIME OF THE EARTH'S OUTER SHELL

Abstract

The paper presents the results of theoretical and experimental research on the justification of the location of the wells of the hydrothermal heat pump system for stable and efficient production of low-potential geothermal energy. It has been proven that the most effective are heat pump systems that use the heat of the soil or groundwater and have heat exchangers and wells installed at a depth below the neutral layer. Endogenous and exogenous factors affecting the depth of the neutral layer are given. It was determined that exogenous factors compared to endogenous factors have a greater influence on the formation of the thermal regime of the hydrosphere. The general regularities of changes in the thermal regime of the hydrosphere under the influence of exogenous factors are given. It is substantiated that, depending on the hydrogeological conditions, the zones where the wells of the geothermal pump system are located, below the theoretically determined depth of the neutral layer, zones with a significant deviation of the soil temperature may re-form. The criteria determining the type of hydrogeothermal regime are determined and the classification of types of hydrogeothermal regime is given. An experimental heat pump system developed and constructed at the Institute of Renewable Energy of the National Academy of Sciences of Ukraine is presented, which consists of a heat pump and two wells through which water circulates from the underground horizon to the heat pump. Temperature sensors are installed in the well and on the surface. Research methods have been developed. The results of experimental studies are presented, based on which it was established that due to the special geomorphological conditions of the location of the system, the water temperature in the aquifer (at a depth of 50 m) depends on the air temperature and the intensity of solar insolation during the day. It has been proven that there is a hydraulic connection between the aquifer opened by the wells and the ponds located in a row in the beams, and the small distance between them and the special topography of the area affect the change in the temperature of the water in the well 50 m deep. The main regularities of the effect of surface harmonic temperature changes on the temperature regime of the Earth's outer shell are outlined. The classification is given, which takes into account all possible main types of hydrogeothermal regime. The results obtained during the research have important scientific and applied significance in the design of geothermal and hydrothermal heat pump systems. In addition, further research into the possibilities and effectiveness of using the aquifer as a natural heat accumulator for stable energy generation from renewable sources regardless of climatic conditions and seasons is promising.